Incidence of oral cancer occult metastasis and survival of T1-T2N0 oral cancer patients

Abstract

Purpose: In head and neck cancer, the most important prognostic factor is the presence or absence of neck metastasis. Although still debated in the published data regarding the "wait and see" policy for Stage T1-T2 oral cancer, a large number of clinicians support the necessity of neck dissection, especially in cases of oral tongue carcinoma, because of the poor prognosis and high risk of recurrence. The aim of the present study was to summarize and quantify the incidence of occult metastasis in oral cancer treatment at the oral and maxillofacial surgery department, Rambam Medical Center, in the past 10 years.

Patients and methods: A total of 142 neck dissections performed at our department in the past 10 years (1998 to 2009) and a series of 68 patients (44 men and 22 women) treated for Stage T1N0 or T2N0 oral cancer were included in the present retrospective study. All patients underwent surgical resection of the oral cancer and selective neck dissection of the ipsilateral side.

Results: Occult lymph node metastases were detected in 11 patients (16% overall, 9 in the tongue, 1 in the buccal mucosa, and 1 in the gingiva of the mandible). The frequency of occult metastasis from tongue carcinoma was 34% (9 of 26 cases). The 5-year survival rate in the present study was 78.9%. In patients who underwent chemotherapy, radiotherapy, brachytherapy, or a combination of the 3 after surgical management, the overall survival rate decreased significantly to 22.5% (P = .006, log-rank test).

Conclusion: The incidence of occult metastasis in patients with oral cancer in the present study was 16% overall. In those with tongue carcinoma, a much greater incidence (34%) of occult metastasis was detected. Furthermore, the need for chemoradiotherapy after initial surgical management, mainly because of occult metastasis, was a significant negative predictor of patient outcome. The results of the present study emphasize the need for prophylactic neck dissection in patients with oral cancer diagnosed with Stage T1N0 or T2N0 disease, especially when the primary lesion is localized in the tongue.